This invention relates to a remotely-operated chain saw for cutting tree branches beyond the reach of a person standing at ground level underneath a tree. In some respects the invention might be considered an improvement or variant on the structural arrangement shown in U.S. Pat. No. 4,341,017 to J. Janczak.
The Janczak patent shows an arrangement wherein an engine 23 is located at the lower end of a tubular handle 2 to drive a hydraulic pump 24. Hydraulic lines 4 and 5 extend within tubular handle 2 to a hydraulic motor 13 located at the upper end of the handle. A chain saw apparatus is connected to the hydraulic motor for cutting tree branches.
My invention seeks to improve the apparatus of the Janczak patent in two respects. First, I have designed the elongated handle structure to include two telescopically-connected tubes, such that the apparatus can be extended or retracted to reach tree branches at various different locations along the tree trunk, e.g. fifteen or more feet from ground level.
Second, I provide an adjustable connection between the chain saw and the tubular handle, whereby the cutter chain can be positioned at different inclinations across the tree branch, e.g. resting directly on the upper surface of the branch or inclined against a side surface of the tree branch, depending primarily on available clearances.
My apparatus is designed to minimize the weight imposed on the chain saw apparatus at the outer (upper) end of the elongated tubular handle. Rather than using a hydraulic motor at the upper end of the handle, I drive the saw apparatus mechanically from ground level via a rotary shaft means extending coaxially within the tubular handle. The drive mechanism comprises a right angle gear box at the upper end of the elongated handle.